RAW really doesn’t help you a ton on sharpness or resolvable resolution for that matter. Yes it can help but it isn’t absolutely required. RAW helps most with noise reduction, pulling for dynamic range, and accurate color reproduction.

Right now an electronic shutter mode is absolutely essential for short exposures with a telescope. That are a few ways to get around this though.

You can get a black sheet of paper and place it in front of the scope when you press the shutter release button. If you set the exposure to 4-8 seconds and then use the piece of paper as a manual shutter you can essentially make an electronic/vibrationless shutter.

Good idea

You can also put a very dark moon filter on the scope and use a high powered barlow. That will allow you to shoot at very long shutter durations that are not affected as much by shutter vibration.